How does familiarity with a person affect trait ratings?

From only a single spoken word, listeners can form a wealth of first impressions of a person’s character traits and personality based on their voice. However, due to the substantial within-person variability in voices, these trait judgements are likely to be highly stimulus-dependent for unfamiliar voices: the same person may sound very trustworthy in one recording but less trustworthy in another. How trait judgements may change when listeners are familiar with a voice is unclear: Are listeners who are familiar with the voices as susceptible to the effects of within-person variability? Does the semantic knowledge listeners have about a familiar person influence their judgements? In the current study, we aimed to empirically test the effect of familiarity on listeners’ trait judgements from variable voices, by tracking how first impressions may differ from second (or “lasting”) impressions. For this purpose, we conducted a series of 3 experiments in which we contrasted trait judgments for listeners who were familiar with a set of voices – either through lab-based training or through watching a TV show – with listeners who were unfamiliar with the voices. We predicted that familiarity would reduce variability in trait judgements for variable voice recordings from the same identity (cf. Mileva, Kramer & Burton, 2019 for faces). However, across the 3 studies and two types of measures to assess variability, we found no compelling evidence to suggest that trait impressions were systematically affected by familiarity.